This ex-military hacker has fought terrorists online since 2010, and he’s not impressed by Anonymous

He’s defaced and shut down hundreds of terrorist websites, inserted false stories into Libyan newspapers, and unmasked fellow hackers who have crossed him.

His name is “The Jester” and he has worked alone as an anonymous hacker vigilante since 2010.

Though the international “hacktivist” group Anonymous declared cyber-war against ISIS on Monday, The Jester is not among them. In fact, he’s among the group’s sharpest critics.

“All they will do is dump a random list of names from a previous hack and claim it’s ISIS members, and they will report ‘ISIS’ accounts to Twitter. Pretty standard BS from them,” The Jester, who goes by the @the3j35t3r handle and keeps his identity closely-guarded, told Tech Insider in an interview over Twitter.

In a video released to YouTube following the terrorist attacks on Friday in Paris, France,Anonymous vowed “massive cyber attacks” while launching its “biggest operation ever against [ISIS].” The group then released a listing of nearly 10,000 Twitter accounts it said were linked to ISIS.

This isn’t the first time ISIS has drawn the scorn of the hacker collective. In August 2014 the group also “declared war,” later revealing what it claimed were approximately 10,000 ISIS-linked social media accounts, according to The Christian Science Monitor.

But even Anonymous may err amidst a confusing battlefield in Iraq and Syria. Among its listing of “target” websites that clearly are in support of the Islamic State, there were some others which were questionable: One site had nothing more than placeholder content (headline: “Modern Concept And Charming Kitchen Design Ideas”), while another was an academic research site intended to track Russian-speaking foreigners who travel to Syria.